Thinking about Kang in a more general sense; would any occurence pre the 31st century matter to him? He didn't make his discovery until then.
I dunno if they'll go into all that in detail.
But if I had to guess, given the fact that the TVA can time travel I'd imagine he'd have interest in any possible time line where a variant would occur.
Like, butterfly effect shyt where things that happened centuries before his discovery, led to the events he described in "Loki".
It has to be something like that because other wise the events in "Loki" wouldn't matter, as they were long before the 31st century.
Fred.